Serotonin and norepinephrine are known to be important chemical messengers participating in the transmission of nerve impulses in the brain. These messengers are liberated at specific sites on pre-synaptic cells and received, to complete transmission of the impulse, at specific sites on post-synaptic cells. Their effect is then terminated by metabolism or by uptake into the pre-synaptic cells. Drugs capable of blocking the pre-synaptosomal uptake of norepinephrine in the brain, thereby alleviating norepinephrine abnormalities at adjacent post-synaptic receptor sites, comprise a major category of antidepressant agents. It is also becoming a widely held view in the medicinal chemistry field that drugs capable of blocking the pre-synaptosomal uptake of serotonin in the brain will comprise another major category of antidepressant agents.
U.S. Pat. Nos. 4,029,731 and 4,045,488 disclose a series of 4-phenyl-1,2,3,4-tetrahydro-naphthalen-1-amines and substituted amines useful as antidepressant agents. The preferred embodiment disclosed in these patents is the enantiomer trans-(1R)-N-methyl-4-phenyl-1,2,3,4-tetrahydro-1-naphthalenamine and its pharmaceutically acceptable acid addition salts.